If you are talking to me, I did recirc the solution with a 1000L/hr pump in my 80 gallon res pumping waterfall style in the tub constantly. The table only got flooded a couple times a day. With ebb and flow the aeration of a couple daily flood/drain on the table, and the pump recirculating the tub the rest of the time seems to be all I needed. Res temps are nowhere near the issue in Ebb&Flow as it is in DWC or RDWC especially if you are using Grodan/Rockwool imo, and I have done both. That said, bennies won't hurt you either.

I had a wild thought last night. I think I can squeeze in 3ea of these 5 gal totes in my tent. That means I could run my original Ebb/Flow in one tote, and the Meniscus/Mat/NFT in the second tote, and the Meniscus Membrane in the third tote.

All would have seeds from the same strain, under the same lighting, same rez and same nutes, same temps, etc etc.

Im pretty sure I can run all three with my airlift pump. At worst, I would need to add a second airlift, but that would only cost me an additional $2 or so in fittings. Actually, I think I have enough fittings laying around to do another one or two.

These seeds are not sexed, so I would need to start at least 6 to be sure I ended up with three females, but Im sure I can fit two in each tub, and then cull the males and smaller female plants.

That would really only cost me the price of one extra tote and a few fittings to rout water around.

That would/should give a really good comparison as to which method works best under the same exact conditions. There would still be the variable you get from one seed to another, but I have no clones, so this would have to do.

I am bored while I wait for this grow to finish, so I decided to go back to testing various auto siphons. There are several variations on YouTube. Most are the Bell type, but there are also T siphons and simple loop siphons. In my earlier tests, a simple loop siphon worked just as well as the bell or the T and it is easier to make and only requires 2ea 90 deg elbows and some pipe.

There was one variation on the loop siphon that used 45 deg elbows - a bunch of them - to create the loop. The main advantage to that version was it has the smallest volume of trapped air at the top when the container fills up. I found that having less air trapped in the siphon made for faster tripping and more reliable tripping at slower fill rates. All that trapped air has to be sucked out before the siphon will trip and flow fully. If it doesnt trip, then the water ends up flowing out just as fast as it flows in, and the container stays full and never drains. Once the air is all gone, the siphon will go full speed and drain the container.

Here is a crude drawing of the various types of auto siphons. Ive tried several Bells and the T and the loop with the 2ea 90 ells. I havent tried one on the far left with the 45 couplings yet. I think the ones with the 45 at the top will be the most reliable and easiest to trip because they will have the least amount of trapped air. My simplified version is on the far right - it uses one less 90 ell. Im going to try it out later tonight.

The tests took a little longer than they might have because I had my 7 yr old grand daughter helping, but they went very well

The loop siphon with the 45 deg on top seems to trip a good bit easier than the others, allowing me to slow down the fill rate and still get reliable trips.

I added a 'P' trap under the tote per one of the YouTube videos I saw, but Im not sure if it really helps or not. I need to do another series of runs with and without the trap. The trap is supposed to 'burp' as the tote fills and trip the siphon that way even with very slow fill rates, but I didnt see any burps.

That may be because I was pretty distracted with all the super enthusiastic help from the 7 yr old. After she traced the water flow from the rez, to the pumping chamber, up through the airlift pump, over to the tote, down through the siphon and back into the rez, she announced that this was just like the cycle of life she learned in class! Pretty sharp kiddo

Here are some pics.

The first two are the airlift pump parts and assembled.

Next is the siphon and 'P' trap assembly.

This is the siphon inside the tote. Its set about 2" below where I want the water level to max out.

Water is just starting to flow over the top of the siphon at a slow rate. It is NOT tripped yet.
Just a slow trickle back into the rez

The siphon has tripped and the tote is draining. Takes about 3 minutes to drain 5 gals.

I can set the minimum water level by cutting the 1/2" CVPC pipe and the small air line tube. The small tube lets air in and assures the siphon stops at that level.

Im going to use something like this plastic jar to cover the siphon to keep stones and roots out of it. The top will be even with the hydroton with a cap on it. I can remove the cap and look inside to check it every so often to be sure its clear.

I think the ideals presented here are all pretty cool but I'm thinking as far as pumps go, is there really a difference between air and water for reliability? Also I know when I was running air stones I had water stability issues re ph, not sure if it would have any effect using in this app though. It will be cool to see how this all rolls out. I've decided to stick with what I do for the next run as I'm running out of smoke and can't afford dialling in a new setup, I get pretty fast growth now .

Yeah, the difference in reliability and even cost, is really fairly minimal between using a water pump or not. The only real reason not to use one is heat in the rez. In a smallish rez, a submersible pump could add significant heat.

Ive been thinking about the differences between the various types of hydro and it all comes down to the ratio between water and air to the roots.

On one end of the scale, you have DWC, water farms, and hempy buckets. They all have a significant % of the roots in water full time.

Next is Ebb/Flow, which in some cases also has a portion of the roots wet 100% of the time, but most seem to drain 100% from what I have read. Ive seen some people who flood a lot and some who only do it 4 times a day, so there is a wide range here.

Next would be the various NFT setups and low pressure aero. Again some of them flow a lot of water and some very little, so how 'wet' the roots are varies a lot.

The highest ratio of air to water looks to me to be the membrane meniscus setup, but I guess the fogger/mist type hi pressure aero systems would be pretty close.

My point being that all of these systems can produce excellent results - if done correctly. I actually dont expect to see a huge difference between the three techniques Im going to try, but it will be fun and interesting to see how it works out.

Yeah, the difference in reliability and even cost, is really fairly minimal between using a water pump or not. The only real reason not to use one is heat in the rez. In a smallish rez, a submersible pump could add significant heat.

Ive been thinking about the differences between the various types of hydro and it all comes down to the ratio between water and air to the roots.

On one end of the scale, you have DWC, water farms, and hempy buckets. They all have a significant % of the roots in water full time.

Next is Ebb/Flow, which in some cases also has a portion of the roots wet 100% of the time, but most seem to drain 100% from what I have read. Ive seen some people who flood a lot and some who only do it 4 times a day, so there is a wide range here.

Next would be the various NFT setups and low pressure aero. Again some of them flow a lot of water and some very little, so how 'wet' the roots are varies a lot.

The highest ratio of air to water looks to me to be the membrane meniscus setup, but I guess the fogger/mist type hi pressure aero systems would be pretty close.

My point being that all of these systems can produce excellent results - if done correctly. I actually dont expect to see a huge difference between the three techniques Im going to try, but it will be fun and interesting to see how it works out.

Click to expand...

Yes I'm running ebb & flow I guess lol. I typically run the pump in cycles but have ran continuos as well so a hybrid and also ran sprayers by basically changing out manifold. Keeping the water chilled has really made a huge difference, took me a bit to get that part being stubborn and also not being able to access hydroguard as of a year ago pushed me. It's a blast to try different setups and I spend a lot of time building controls. I really only started hydro about 6 years ago, grew outdoors before that for 45 years .

They can also be had on ebay for just over $2 each, but I think I would go Amazon. I already have thermal paste, a power supply, marine sealant, and heat sink material I can use.

Im picturing cutting rectangular holes the size of these (2"+-) in the sides of my rez, then gluing a heat sink on the inside of the hole that seals the hole but leaves the heat sink exposed on the outside. Then ataching one or more of these to the exposed portion of the heat sink on the outside with a small fan blowing on them. I will probably have to add another heat sink on the outside as well. Im planning on just using cheap alum U channel I have on hand.

The 'cool' part of using these, is they can also heat the water just by reversing the current flow. With a simple STC 1000 ($15) or similar thermostatic controller, you can keep your rez cooled or heated as needed all year round.